Q&A Forums

warped ceiling Post New Topic | Post Reply

Author	Comments
stan seidel Posted: Nov 11, 2009 03:46 PM	warped ceiling last fall the ceiling of my new home was sprayed with a product called heat lok soy from demilic. this summer I noticed that the ceiling was warped in an upward direction up to 1/2" between the trusses, does anyone have any idea what would cause this ? the manufacturer claims it was caused from moisture and because the home is by a lake? but since the foam adheres to the sheetrock and the foam is somewhat ridgid and a vapor barrier I dont see how the moisture could force everything in an upward direction ?
mason Posted: Nov 11, 2009 04:22 PM	I have seen drywall warped and cracked due to foam shrinkage. Check out the attic and see if the foam is shrinking. You might have to get it redone in those areas.
stan seidel Posted: Nov 11, 2009 06:53 PM	My guess is shrinkage also, but how could I tell by looking at it? right now it is covered with about 6" of cellulose but if I swept it away would I be able to tell ? Thank you Stumpy
mason Posted: Nov 12, 2009 02:37 PM	Right, go to the area right above the warped drywall and sweep the cellulose away from that section. I would bet that the foam has pulled away from the floor joists or rafters (depending on if the foam has been installed to the underside of the roof deck or the floor of the attic).
Posted: Nov 13, 2009 08:53 AM	moisture and living by a lake...rofl...lips were movin i bet....this is when we should use this product,,,derr,,, that being said,,,lets try and be proactive,,, stumpy,,,need a few particulars before i can make comment,,,this may not be foam shrinkage at all,,, where your homes truss system an engineeered (stamped) (sorry had to..isnt always the case,,and to assume....) what climate zone are you in??? how cold does it go and how hot does it go??? did you and your new home go thru a summer/winter cycle and then you notice this malady???or has the environmental conditions been static and the change still noticed over time... is this a closed cell foam or a open cell foam... specifically,, density???depth sprayed???what is the depth of the bottom frameing member of the truss assembly(ie: 2x4,,,2x6,,,or what ever,,,and we should assume wood not metal construction???(sorry had to)... got a few idea's and considerations... will check back with ya later... ...i saw the tree,,, on down the hill... i hit a bump,,, and took a spill,,, burma shave
stan seidel Posted: Nov 13, 2009 10:05 AM	Thanks foamdude for your time. yes the trusses are engineered 2x6. keep in mind that the trusses are not sucked up with the sheetrock, only the sheetrock between the trusses is sucked up. the home is in Minnesota,temps can go below -20 deg. to around 100 deg. the home was sprayed in the fall to a total of 2" thick sprayed in 2 passes and went through a winter and the home was kept heated to around 50-55 degrees and had an air exchanger running. we did not notice the sheet rock was sucked up until about aug or sept. Thanks again Stumpy do they still make burma shave ?? dont take any wooden nickles
Posted: Nov 14, 2009 09:36 AM	...sorry stumpy.. was thinkin about an expansion/contraction thingy(frameing members) i seen a few times with cc in attics... but yours does not seem to reproduce those conditions,, ???mason??? how soon would cell collapse occour in a mis-propoertioned applicaton??? could there be other products aged dimensional stability type issues playing here as well??? i believe the burma shave brand is still in production...but back when phillip morris bought them they did way with those way cool signs,,,seems they thought it was way to hazardous to our health to have us readin signs while drivin...with our other finger poised on the lighter... a plumber dude in town built the worlds largest wooden nickel,,guiness book of dark beer im told
jimcoler I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs. I've expanded my knowledge into t Posted: Nov 16, 2009 10:00 AM	Stumpy, It seems moisture can play a role in the flexibility of the sheetrock - much like moisture allows us to bend wood into arcs and circles for chairs. The more moisture in the drywall, the more flexible and susceptible it will be to warping. So, if it was sprayed when the moisture content was high inside the house, then this could be the issue. As the foam cools, it will shrink like any plastic heated material will, and if the sheetrock isn't ridgid enough to hold the shrinking force, we get warping. Were the drywallers or painters using unvented propane heaters inside before you sprayed the lid? Does the basement/crawlspace have any visible moisture or vapor barriers installed?
mason Posted: Nov 16, 2009 10:19 AM	Foam shrinkage can occur within a few days or can take months. If the foam is not mixed well, it can have less than 90% closed cell content (60 to 75%) and leave weak foam cell structure. Also, if it is applied in too thick a lift or another lift installed too soon, excess exothermic heat can be created. The excess heat (more than 220 degrees F) can also cause the foam cell structure to be weaker and more likely to shrink. I have seen foam shrinkage cause drywall warpage in a half a dozen projects I was called in to inspect. I can't say that this is the specific reason in your situation. As others have pointed out, damp drywall or framing members can caused warpage also. Were you able to check out the foam shrunk back from the joists or rafters in the areas where the drywall is warped?
stan seidel Posted: Nov 17, 2009 04:33 PM	I did examine the insulation today, and I could not see any signs of cracking. but this foam seems very pliable and I wonder if could influence the sheetrock without cracking? either way the foam does not seem to be cracked weather being caused by moisture or shrinkage? But why would the sheetrock warp in an upward direction if it wasnt influenced by the foam, even if the sheetrock contained moisture? I have never seen sheetrock warp in an upwards direction with fiberglass or cellulose, it always sags down when it contains to much moisture. also why wouldnt the warping show up shortly after foaming instead of after 6-8 months ?especially after going through a winter with being heated.
mason Posted: Nov 18, 2009 06:27 AM	Yes, the foam could cause drywall to warp without showing cracks. The foam could be stressed but extremely well adhered to the wood framing and the drywall. The wood doesn't give but the drywall does. The stress slowly exerts more and more pressue on the drywall eventually causing it to warp. This stress may also eventually cause the foam to crack. Try cutting a line 2 ft long between the wood in the foam around 3 inches deep. Sometimes the foam will shrink back more and crack right along that line (immediately or after a few days). If that is the case, then I think you have found your problem.
jimcoler I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs. I've expanded my knowledge into t Posted: Nov 18, 2009 01:57 PM	It can pull up because foam is a plastic material. If you heat a plastic material, it will expand with higher heat than if you cool it. As it cools, it will contract. It's called the coefficient of thermal expansion (CoTE)and different materials have different CoTEs. As the foam is sprayed to moist drywall, it will cool faster because the heat is absorbed into the moisture than the rest of the foam. Also, the thicker the foam, the more it will shrink because of the difference of cooling in the core of the foam to the exterior extremeties.
Gerry Wagoner Posted: Nov 20, 2009 08:50 AM	My guess is that it was sprayed too much too thick too fast. g
stan seidel Posted: Nov 26, 2009 09:34 AM	Jimcoler Thanks Jim We need to keep in mind that the warping occured during the months after the foam was applied. the foam was applied in the fall and we didnt notice the problem until min summer. Is it possible that the foam mixture was incorrect and it continued shrinking, and since the foam is thicker where the truss and drywall meet and because of a thicker cross section in that area it would shrink more in that area, and tend to pull up on the drywall therefore, causing it yield gradually under the continued stress? Maybe Mason could also respond to this theory? Thanks Stumpy
Grady Littlehale Posted: Nov 26, 2009 06:16 PM	Stumpy, Do you know what kind of sheetrock it was? There is alot of "stuff" happening right now with the sheetrock indusry( importing "bad" rock from china. Also the American made stuff is being looked at as well. Something too look into.
stan seidel Posted: Nov 26, 2009 07:53 PM	Thanks for your reply I have reasearched that possibility, I believe the sheetrock was GP, The specific product is a high strength sheetrock for ceilings. I have some pieces left over in my pole barn and they are still straight, my walls are straight. I have talked to 4 different drywall contractors and a painter that came to give me bids on repairing the problem and they said that they have never seen anything like this before, they all agree that it must be something with the foam because normaly if anything, the sheetrock would warp in a downward direction, not up? It would be defying gravity and also forceing the ridgid foam up. kinda like lifting yourself up by your bootstraps.
mason Posted: Nov 26, 2009 09:35 PM	If the foam has caused the problem, it can be checked out. Typically the foam would have low compressive strength in the middle of the foam pass also, it might have more open cells than normal. For example, 60 to 70% closed cell content instead of 90% as it should. Both of these problems can be caused by one or more of the following issues, an inadequate mix, thick foam passes, high humidity of air and/or substrate, high exothermic heat and an off spec foam.
stan seidel Posted: Nov 26, 2009 10:15 PM	How would I be able to check that ?? can you recomend a company that could do this for me other than the manufacturer?
Edward Brassington Posted: Nov 30, 2009 09:59 PM	Hello Stumpy I have just read your posts and comments from others. I spray the same product and have found it to be an excellent foam. In one post you mentioned that the foam seemed "quite pliable". Two pound closed cell foam is usually not pliable, it is fairly rigid. Has anyone done a density check on the foam. If not I would be happy to perform a density check for you. If you could cut out a couple of different samples approx 6 inches long and full depth of the foam, send them to me and I will see what I can do. I am located in Canada so I won't be able to help you much beyond a density check. It sounds to me, that the foam was sprayed of ratio and has not cured properly. I believe you also said that the total depth of the foam is two inches. Two inches of foam should not have caused any distortion whatsoever. What is the span of the trusses, are they 24"? Also do you get a lot of snow in your area? Approximately how much snow accumulated on the roof last winter? Perhaps accurately measure the distance from the floor to the bottom chord of the truss, do this along the outside edges and in several spots in the middle of the house. Is it the same? I have seen a roof do this before, it was assumed that the drywall had bowed upwards, when in fact the trusses had been pushed down due to snow load. The foam had remained in place. This wasn't Demilec foam it was another product. You may also need the advice of a professional engineer to make sure the structure is solid and as built. Feel free to contact me by email and I will send you my mailing address for the density check.
stan seidel Posted: Dec 01, 2009 03:29 AM	First thing, thank you for taking the time to respond to my post, I do appreciate it. At this point I would like to email some pics of my ceiling and maybe they would give you a better idea of what is happening. The snow load was way down from last year so I do not think that was a problem, the trusses were engineered by lampert lumber company or their supplier so I am guessing that they are ok. It seems strange to me that it would be that in the case you mentioned that the trusses bowed down and the foam and sheetrock stayed in place? I will gladly send you a sample to test when you send me your address. Could you tell me how the density test is done ? I am curious. I am not questioning the quality of demilics product but I do have an issue with their support in this case, when something goes wrong as in this case they should step up to the plate. Thanks again Stan
mason Posted: Dec 01, 2009 07:22 AM	Stumpy, You asked earlier how you could obtain the data that you need. A large part of my consulting business is conducting onsite inspections and foam analysis when something goes wrong. In the last 2 years I have been on more than a dozen projects where the foam has cracked and/or shrunk, sampled the foam, conducted density and compressive strength analysis, provided an opinion to the cause of the problem and recommendations for repair. This typically takes an onsite visit at my daily rate followed by 4-6 hours or work at my office doing the sample analysis and writing the report. I have been hired to perform this work by suppliers, contractors, building owners and insurance companies. The reports have been used to settle disputes in many cases without getting lawyers involved. In the few cases where the issue goes to court, my reports have been highly influential in the ultimate decision. Let me know if you would like an estimate of the work. contact me at masonknowles@aol.com